Diagnostic Imaging: Introduction. Contents. Conventional Radiography Computed Tomography Ultrasonography Magnetic Resonance Imaging Nuclear Medicine. Conventional Radiography . Fluoroscopy Mammography Contrast Studies. Contrast Studies. Barium suspensions
Conventional radiography remains a fundamental tool in the detection and diagnosis of disease presenting in the chest , abdomen, pelvis, breasts, and bones.
US-guided core biopsy or fine-needle aspiration (FNAC)
Retrograde studies of the renal collecting system (retrograde pyelography), ureter (retrograde ureterography), and bladder (cystography)
An AP film from an intravenous urogram taken at 10 minutes in a pt. with a proximal Lt ureteral calculus (arrow) and associated left collecting system dilatation. The right collecting system is normal, and the right ureter (arrowheads),bladder are seen.
In patients suspected of having a pulmonary embolus, pulmonary angiography may be performed.
Contrast-enhanced CT image of the upper abdomen demonstrates two low-attenuation areas (M) confirmed as multiple hepatic metastases from gastrointestinal stromal tumor.
A transverse ultrasound image of the gallbladder demonstrates a gallstone (arrow) with the characteristic distal acoustic shadowing (S) because sound waves cannot penetrate the gallstone.
Endoluminalsonography is used to image structures beyond the lumen of the hollow viscus.
d. The uterus, adnexa, and routine fetal examinations by using a transvaginal probe in the presence of an empty bladder.
f. Transesophageal echocardiography is used for evaluating cardiovascular abnormalities after placement of a probe into the esophagus.
g. Three-dimensional ultrasound (3D-US) is widely used in obstetrics and vascular imaging.
In MR imaging, a pulsed radio-frequency (rf) beam is used in the presence of a strong main magnetic field to generate high-quality images of the body.
eg. intracranial aneurysm clips, intraorbital metallic foci, cardiac pacemakers, or specific types of cardiac valves.
Nuclear medicine studies are performed by administering a radiopharmaceutical to the patient and subsequently recording its distribution in the body over a defined period of time.
e. gastrointestinal bleeding studies for detection and localization of small bleeds,
f. lymphoscintigraphy to identify sentinel lymph nodes for surgery, and
g. parathyroid scans to identify adenomas and hyperplasia.
A 99mTc-MDP bone scan in the anterior and posterior projections demonstrates multiple foci of increased radiopharmaceutical accumulation (spine, ribs, pelvis, and left clavicle) with the typical appearance of bone metastases.